Production of pure aluminum by electrolysis of aluminum chloride, in turn produced by conversion of carbon-coated alumina particles, is well known; U.S. Pat. Nos. 3,811,916--Russell et al and 3,904,494--Jacobs et al. The Russell et al patent teaches specifically the production of such carbon-coated alumina particles by fluid bed cracking and prior or concurrent deposition of crackable hydrocarbons on particulate alumina. For this purpose, Russell et al indicates that normally liquid hydrocarbons are preferred and fuel oil, such as No. 6 fuel oil and commercial Bunker C fuel oil, are economically preferred types thereof. This process is carried out, according to the Russell et al patent, in a two-stage fluid bed process, so as first to coat alumina particles with crackable hydrocarbon and then separately to crack the crackable hydrocarbon both in vapor and deposited form in the presence of the alumina particles. Gaseous effluent, presumably containing some cracked light hydrocarbon gases and hydrogen may be recovered and used as fuel or fluidizing gas in the process.
Other processes are also well known wherein hydrocarbon compositions, including crude oil and crude oil fractions, are thermally cracked in the presence of particulate alumina, as shown for example in U.S. Pat. Nos. 2,556,514--Bergstrom; 2,894,897--Post; and 2,937,136--Moser, Jr. Carbon deposits on the alumina particles in such processes are a common factor, dealt with for example by stripping and/or burning off the carbon from the alumina with steam. As suggested in the Post patent, the coke-coated alumina may be reacted with steam to produce hydrogen which is recycled to the cracking stage, effectively to hydrocrack the hydrocarbons there.
U.S. Pat. Nos. 2,861,943--Finneran et al; 2,913,396--Johnson et al; 3,033,779--Fidelman; and 3,202,603--Keith et al, all assigned to Hydrocarbon Research, Inc., pertain to such a process wherein the hydrocracking, at high temperature and high pressure, is integrated, such as in a single shell reactor with multiple stages of fluidization and reaction therein, with the alumina particle reaction and conversion to produce the hydrogen-containing atmospheres for hydrocracking. For purposes of comparison to the present invention, it should be noted that the Keith et al patent specifically deals with a high boiling point feedstock, such as a residual oil fraction, and suggests converting it primarily to high value gaseous products, comparable what is referred to herein as synthetic natural gas.
Notwithstanding this prior art, there remains a need for more efficiently converting high boiling point hydrocarbon fractions, such as residual oil fractions of crude oil, typified by vacuum still bottom residue, or heavy crude oil per se, such as Boscan crude, into upgraded products. Particularly, there remains a continuing need for producing such upgraded products in a simplified manner to enhance the cost effectiveness of such processes.
It is therefore the general object of the present invention to provide such a process.